talk to your partner.
What are you doing now?
When did you start doing it?
How long have you been doing it?

1) What are you doing now? I'm watching a film. When did you start watching it? I began watching it at 3 p.m. How long have you been watching it? I have been watching it for two hours. 2) What are you doing now? I'm reading a book. When did you start reading it? I began reading it two days ago. How long have you been reading this book? I have been reading it for two days. 3) What is she doing now? She is solving a puzzle. When did she start solving a puzzle? She began solving a puzzle two hours ago. How long has she been solving a puzzle? She has been solving a puzzle for two hours.